/// <summary>
/// Obtains the common default properties for multiple objects</summary>
/// <param name="items">Items with properties</param>
/// <returns>Default properties all shared by multiple objects</returns>
/// <remarks>Some of the descriptors may be MultiPropertyDescriptor so that all the items can share them.</remarks>
public static IEnumerable<PropertyDescriptor> GetSharedProperties(IEnumerable<object> items)
{
List<PropertyDescriptor> result = new List<PropertyDescriptor>();
bool firstTime = true;
foreach (object item in items)
{
IEnumerable<PropertyDescriptor> properties = GetDefaultProperties(item).Cast<PropertyDescriptor>();
if (firstTime)
{
firstTime = false;
result.AddRange(properties);
}
else
{
for (int i = 0; i < result.Count; )
{
string key = GetPropertyDescriptorKey(result[i]);
// Check the item for a matching property descriptor
// If found: replace normal descriptor with MultiPropertyDescriptor in the result
// Otherwise: Remove the property from merged properties
PropertyDescriptor matchingDescriptor = FindPropertyDescriptor(item, key);
if (matchingDescriptor != null)
{
var multiDescriptor = result[i] as MultiPropertyDescriptor;
if (multiDescriptor == null)
{
multiDescriptor = new MultiPropertyDescriptor(result[i]);
result[i] = multiDescriptor;
}
i++;
}
else
result.RemoveAt(i);
}
}
}
return result;
}
public void TestGetPropertyDescriptorKey()
{
// First use AttributePropertyDescriptor and MultiPropertyDescriptor
{
// Make sure that different property descriptor objects with the same Name, Category and Type
// have the same hash code, using PropertyUtils.GetPropertyDescriptorHash().
var attrPropertyDescriptor = new AttributePropertyDescriptor(
"TestName", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
"TestCategory", "Test description", false);
var multiPropertyDescriptor = new MultiPropertyDescriptor(attrPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(attrPropertyDescriptor, multiPropertyDescriptor));
// Make sure that null Category names work, too.
attrPropertyDescriptor = new AttributePropertyDescriptor(
"TestName", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
null, "Test description", false);
multiPropertyDescriptor = new MultiPropertyDescriptor(attrPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(attrPropertyDescriptor, multiPropertyDescriptor));
// Make sure that if the Name and Category and identical, that it works with other property
// descriptors who also have identical Name and Category strings. This makes sure that we
// are not using 'xor' between the Name and Category.
attrPropertyDescriptor = new AttributePropertyDescriptor(
"SameName", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
"SameName", "Name and Category are the same!", false);
multiPropertyDescriptor = new MultiPropertyDescriptor(attrPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(attrPropertyDescriptor, multiPropertyDescriptor));
var d2 = new AttributePropertyDescriptor(
"AnotherSameName", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
"AnotherSameName", "Name and Category are the same!", false);
var m2 = new MultiPropertyDescriptor(d2);
Assert.IsTrue(IsSameHashKey(d2, m2));
Assert.IsTrue(!IsSameHashKey(attrPropertyDescriptor, d2));
// Make sure that if the Name and Category are swapped, that they yield different codes.
attrPropertyDescriptor = new AttributePropertyDescriptor(
"Name1", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
"Name2", "Test description", false);
d2 = new AttributePropertyDescriptor(
"Name2", new AttributeInfo("TestAttrName", new AttributeType("TestAttrName", typeof(string))),
"Name1", "Test description", false);
Assert.IsTrue(!IsSameHashKey(attrPropertyDescriptor, d2));
}
// Now use a stub property descriptor and MultiPropertyDescriptor
{
// Make sure that different property descriptor objects with the same Name, Category and Type
// have the same hash code, using PropertyUtils.GetPropertyDescriptorHash().
var stubPropertyDescriptor = new MyPropertyDescriptor("TestName", "TestCategory", typeof(string));
var multiPropertyDescriptor = new MultiPropertyDescriptor(stubPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(stubPropertyDescriptor, multiPropertyDescriptor));
// Make sure that null Category names work, too.
stubPropertyDescriptor = new MyPropertyDescriptor("TestName", null, typeof(string));
multiPropertyDescriptor = new MultiPropertyDescriptor(stubPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(stubPropertyDescriptor, multiPropertyDescriptor));
// Make sure that if the Name and Category and identical, that it works with other property
// descriptors who also have identical Name and Category strings. This makes sure that we
// are not using 'xor' between the Name and Category.
stubPropertyDescriptor = new MyPropertyDescriptor("SameName", "SameName", typeof(string));
multiPropertyDescriptor = new MultiPropertyDescriptor(stubPropertyDescriptor);
Assert.IsTrue(IsSameHashKey(stubPropertyDescriptor, multiPropertyDescriptor));
var d2 = new MyPropertyDescriptor("AnotherSameName", "AnotherSameName", typeof(string));
var m2 = new MultiPropertyDescriptor(d2);
Assert.IsTrue(IsSameHashKey(d2, m2));
Assert.IsTrue(!IsSameHashKey(stubPropertyDescriptor, d2));
// Make sure that if the Name and Category are swapped, that they yield different codes.
stubPropertyDescriptor = new MyPropertyDescriptor("Name1", "Name2", typeof(string));
d2 = new MyPropertyDescriptor("Name2", "Name1", typeof(string));
Assert.IsTrue(!IsSameHashKey(stubPropertyDescriptor, d2));
}
}
